/Engine/Source/Runtime/GeometryCore/Public/DynamicMesh/MeshNormals.h
Initialize the given NormalOverlay with per-vertex normals, ie single overlay element for each mesh vertex.
static void InitializeOverlayToPerVertexNormals ( [FDynamicMeshNormalOverlay](API\Runtime\GeometryCore\DynamicMesh\FDynamicMeshNormalOverlay) * NormalOverlay, bool bUseMeshVertexNormalsIfAvailable )